/* 위트앤매쓰 소개 화면.
   파란색 하나로 밀어붙인다 — 도구 화면(/app)이 이미 파랑이라, 소개에서 다른 색을 쓰면
   들어간 순간 «다른 서비스에 온 것 같다»가 된다. 바탕의 모눈은 수학 노트에서 가져왔다. */
*,*::before,*::after{box-sizing:border-box}
:root{
  --blue:#1f8cff; --blue-d:#0f6fd8; --blue-deep:#0a3f80; --blue-soft:#eaf4ff; --blue-line:#b9dcff;
  --ink:#16202b; --ink-2:#4a5765; --ink-3:#7b8794; --line:#e5e8ec; --bg:#fff; --panel:#f6f8fa;
  --green:#12805c; --amber:#ff9500;
}
html{scroll-behavior:smooth}
body{margin:0;background:var(--bg);color:var(--ink);
  font-family:'Pretendard Variable',Pretendard,-apple-system,BlinkMacSystemFont,system-ui,sans-serif;
  font-size:16px;line-height:1.65;-webkit-font-smoothing:antialiased;word-break:keep-all}
img,svg{display:block;max-width:100%}
h1,h2,h3,h4,p{margin:0}
a{color:inherit;text-decoration:none}
.in{max-width:1160px;margin:0 auto;padding:0 24px}
:focus-visible{outline:2px solid var(--blue);outline-offset:3px}

/* ── 머리띠 ── */
.nav{position:sticky;top:0;z-index:30;background:rgba(255,255,255,.92);backdrop-filter:blur(8px);
  border-bottom:1px solid var(--line)}
.nav .in{display:flex;align-items:center;gap:28px;height:68px}
.brand{display:flex;align-items:center;gap:9px;font-size:19px;font-weight:800;letter-spacing:-.035em}
.brand .mk{width:26px;height:26px;border-radius:8px;background:linear-gradient(140deg,#3f9bff,#0f5fc4);
  display:grid;place-items:center;color:#fff;font-size:13px;font-weight:800}
.menu{display:flex;gap:26px;font-size:15px;font-weight:600;color:var(--ink-2)}
.menu a:hover{color:var(--blue)}
.acts{margin-left:auto;display:flex;align-items:center;gap:10px}
.acts .ghost{border:1px solid #d8dce2;border-radius:7px;padding:9px 16px;font-size:14.5px;font-weight:700;color:var(--ink-2)}
.acts .ghost:hover{border-color:var(--ink-3)}
.acts .cta{background:var(--blue);color:#fff;border-radius:7px;padding:10px 18px;font-size:14.5px;font-weight:700}
.acts .cta:hover{background:var(--blue-d)}

/* ── 첫 화면 ── */
.hero{position:relative;overflow:hidden;padding:76px 0 90px;
  background:linear-gradient(168deg,#0d4b96 0%,#1372cf 46%,#2d93f0 100%);color:#fff}
.grid-bg{position:absolute;inset:0;opacity:.2;pointer-events:none;
  background-image:linear-gradient(rgba(255,255,255,.4) 1px,transparent 1px),
                   linear-gradient(90deg,rgba(255,255,255,.4) 1px,transparent 1px);
  background-size:34px 34px;
  mask-image:radial-gradient(ellipse 85% 70% at 50% 12%,#000 30%,transparent 78%);
  -webkit-mask-image:radial-gradient(ellipse 85% 70% at 50% 12%,#000 30%,transparent 78%)}
.hero .in{position:relative;text-align:center}
.kicker{font-size:14px;font-weight:700;letter-spacing:.02em;color:#bfe0ff;margin-bottom:14px}
.hero h1{font-size:clamp(34px,5.2vw,58px);font-weight:800;letter-spacing:-.045em;line-height:1.2;text-wrap:balance}
/* 밑줄처럼 얇게 깐다. 글자 뒤를 네모로 채우면 파랑 위에서 흐린 회색 상자로 보인다. */
.hero h1 em{font-style:normal;background:linear-gradient(transparent 74%,rgba(126,207,255,.55) 0);padding:0 3px}
.hero .sub{margin-top:18px;font-size:clamp(16px,2vw,19px);color:#dceeff;line-height:1.72}
.hero .sub b{color:#fff;font-weight:700}
.hero-cta{margin-top:30px;display:flex;gap:14px;justify-content:center;align-items:center;flex-wrap:wrap}
.hero-cta .big{background:#0b1b2c;color:#fff;border-radius:10px;padding:16px 30px;font-size:17px;font-weight:800;
  display:inline-flex;align-items:center;gap:10px;box-shadow:0 10px 30px -12px rgba(0,0,0,.6)}
.hero-cta .big:hover{background:#050f1a}
.hero-cta .big span{transition:transform .18s}
.hero-cta .big:hover span{transform:translateX(3px)}
.hero-cta .plain{color:#cfe6ff;font-size:15.5px;font-weight:600;border-bottom:1px solid rgba(207,230,255,.5);padding-bottom:2px}
.mo{display:none}

/* 그 자리에서 움직여 보는 상자 */
.demo{margin:44px auto 0;max-width:900px;background:#fff;color:var(--ink);border-radius:16px;
  box-shadow:0 26px 60px -24px rgba(4,26,52,.6);overflow:hidden;text-align:left}
.demo-head{display:flex;align-items:baseline;gap:10px;padding:15px 20px;border-bottom:1px solid var(--line);
  background:var(--panel);flex-wrap:wrap}
.demo-head b{font-size:14.5px;font-weight:800}
.demo-head span{font-size:13px;color:var(--ink-3)}
.demo-body{display:grid;grid-template-columns:1fr 1fr;gap:0}
.demo-fig{padding:18px;display:grid;place-items:center;border-right:1px solid var(--line);background:#fff}
.demo-ctl{padding:18px 20px}
.demo-ctl label{display:block;font-size:13px;font-weight:700;color:var(--ink-2);margin-bottom:14px}
.demo-ctl label b{color:var(--blue);font-variant-numeric:tabular-nums;margin-left:4px}
.demo-ctl input[type=range]{width:100%;margin-top:8px;accent-color:var(--blue);height:5px;
  -webkit-appearance:none;appearance:none;background:#e3e8ee;border-radius:99px;outline:0}
.demo-ctl input[type=range]::-webkit-slider-thumb{-webkit-appearance:none;width:20px;height:20px;border-radius:50%;
  background:var(--blue);border:3px solid #fff;box-shadow:0 1px 5px rgba(16,40,70,.35);cursor:pointer}
.demo-ctl input[type=range]::-moz-range-thumb{width:16px;height:16px;border-radius:50%;background:var(--blue);
  border:3px solid #fff;box-shadow:0 1px 5px rgba(16,40,70,.35);cursor:pointer}
.demo-out{border-top:1px dashed #d8dce2;padding-top:12px;margin-top:4px}
.demo-out .k{font-size:11px;font-weight:800;color:var(--ink-3);letter-spacing:.06em}
.demo-out p{font-size:14.5px;margin:3px 0 10px;line-height:1.6}
.demo-out p#dans{font-weight:800;color:var(--blue);font-size:17px}
.demo-note{margin-top:10px;font-size:12px;color:var(--ink-3);line-height:1.6}

/* ── 공통 섹션 ── */
section.band,section.split,section.price,section.faq{padding:88px 0}
section.dark{padding:88px 0;background:#0e1620;color:#e8edf3}
.tag{display:inline-block;font-size:12.5px;font-weight:800;letter-spacing:.04em;color:var(--blue);
  background:var(--blue-soft);border-radius:99px;padding:5px 13px;margin-bottom:14px}
section.dark .tag{background:rgba(31,140,255,.18);color:#8cc6ff}
h2{font-size:clamp(25px,3.4vw,36px);font-weight:800;letter-spacing:-.035em;line-height:1.28;text-wrap:balance}
.lede{margin-top:12px;font-size:16.5px;color:var(--ink-2);max-width:62ch}
section.dark .lede{color:#a9b7c6}

.cards{margin-top:36px;display:grid;grid-template-columns:repeat(auto-fit,minmax(276px,1fr));gap:18px}
.cards article{border:1px solid var(--line);border-radius:14px;padding:24px 22px;background:#fff;
  transition:box-shadow .18s,transform .18s}
.cards article:hover{box-shadow:0 14px 34px -20px rgba(16,40,70,.4);transform:translateY(-2px)}
.cards h3{font-size:17.5px;font-weight:800;letter-spacing:-.02em;margin:14px 0 8px}
.cards p{font-size:14.5px;color:var(--ink-2);line-height:1.72}
.cards p b{color:var(--ink);font-weight:700}
.ic{display:block;width:34px;height:34px;border-radius:10px;background:var(--blue-soft);position:relative}
.ic::after{content:'';position:absolute;inset:9px;border-radius:3px;background:var(--blue);opacity:.85}
.ic1::after{clip-path:polygon(0 100%,0 20%,100% 100%)}
.ic2::after{clip-path:polygon(0 0,72% 0,100% 26%,100% 100%,0 100%)}
.ic3::after{border-radius:50%}
.ic4::after{clip-path:polygon(12% 52%,40% 80%,90% 14%,100% 26%,42% 100%,2% 62%)}
.ic5::after{clip-path:polygon(0 30%,100% 30%,100% 44%,0 44%,0 62%,100% 62%,100% 76%,0 76%)}
.ic6::after{clip-path:polygon(0 100%,0 60%,26% 60%,26% 100%,38% 100%,38% 28%,64% 28%,64% 100%,76% 100%,76% 0,100% 0,100% 100%)}

/* ── 원본 → 쌍둥이 ── */
section.split .in{display:grid;grid-template-columns:1fr 1fr;gap:56px;align-items:center}
.split .txt p{margin-top:14px;font-size:16px;color:var(--ink-2)}
.split .txt p b{color:var(--ink)}
.ticks{margin:22px 0 0;padding:0;list-style:none;display:grid;gap:11px}
.ticks li{position:relative;padding-left:26px;font-size:15px;color:var(--ink-2)}
.ticks li::before{content:'';position:absolute;left:2px;top:7px;width:12px;height:7px;
  border-left:2.4px solid var(--blue);border-bottom:2.4px solid var(--blue);transform:rotate(-45deg)}
.pair{display:flex;align-items:center;gap:16px;justify-content:center;flex-wrap:wrap}
.pair .one{border:1px solid var(--line);border-radius:14px;padding:12px;background:#fff;text-align:center;
  box-shadow:0 12px 30px -22px rgba(16,40,70,.5)}
.pair .one img{border-radius:8px}
.pair .one p{font-size:13px;color:var(--ink-2);margin-top:8px;font-weight:600}
.pair .lb{display:inline-block;font-size:11.5px;font-weight:800;color:var(--ink-3);
  background:var(--panel);border-radius:99px;padding:3px 10px;margin-bottom:8px}
.pair .lb.on{color:var(--blue);background:var(--blue-soft)}
.pair .arrow{font-size:26px;color:var(--blue);font-weight:700}

/* ── 실시간 퀴즈 ── */
.mock{margin-top:34px;display:grid;grid-template-columns:1fr 264px;gap:22px;align-items:end}
.mock-board{background:#141c26;border:1px solid #26313e;border-radius:16px;overflow:hidden}
.mb-top{display:flex;align-items:center;gap:10px;padding:13px 18px;border-bottom:1px solid #26313e;
  font-size:13.5px;color:#95a4b5}
.mb-dot{width:9px;height:9px;border-radius:50%;background:#3f9bff}
.mb-top b{margin-left:auto;font-size:19px;letter-spacing:.14em;color:#fff;font-variant-numeric:tabular-nums}
.mb-body{padding:26px 24px 28px}
.mb-q{font-size:22px;font-weight:700;letter-spacing:-.02em;line-height:1.45}
.katex-ish{font-family:'Times New Roman',serif;font-style:italic}
.mb-choices{margin-top:20px;display:grid;grid-template-columns:1fr 1fr;gap:11px}
.mb-choices .c{border-radius:11px;padding:13px 16px;font-size:16.5px;color:#fff;font-weight:600;
  display:flex;align-items:center;gap:8px}
.mb-choices .c b{margin-left:auto;font-size:14px;opacity:.9}
.c0{background:#8f3129}.c1{background:#1a4d8f}.c2{background:#a07220}.c3{background:#17603f}
.c.right{outline:3px solid #7ee2a8;background:#c08a26}
.mock-phone{background:#f6f8fa;border:1px solid #26313e;border-radius:20px;padding:12px;color:var(--ink)}
.mp-top{font-size:12.5px;color:var(--ink-3);padding:4px 6px 10px;border-bottom:1px solid var(--line);font-weight:700}
.mp-body{padding:26px 10px;text-align:center}
.mp-q{font-size:17px;font-weight:700}
.mp-ok{margin-top:14px;font-size:22px;font-weight:800;color:var(--green)}
.mp-pts{margin-top:8px;display:inline-block;background:#fff;border:1px solid var(--line);border-radius:99px;
  padding:6px 14px;font-size:14px;font-weight:800}
.two{margin-top:34px;display:grid;grid-template-columns:1fr 1fr;gap:26px}
.two h4{font-size:16.5px;font-weight:800;margin-bottom:7px}
.two p{font-size:14.5px;color:#a9b7c6;line-height:1.72}

/* ── 반 운영 ── */
.flow{margin-top:34px;display:grid;grid-template-columns:repeat(auto-fit,minmax(216px,1fr));gap:16px}
.flow>div{border:1px solid var(--line);border-radius:14px;padding:22px 20px;position:relative;background:#fff}
.flow b{display:grid;place-items:center;width:26px;height:26px;border-radius:50%;background:var(--blue);
  color:#fff;font-size:13px;font-weight:800;margin-bottom:12px}
.flow h4{font-size:16px;font-weight:800;margin-bottom:6px}
.flow p{font-size:14px;color:var(--ink-2);line-height:1.7}

/* ── 요금 ── */
.price{background:var(--panel)}
.plans{margin-top:34px;display:grid;grid-template-columns:repeat(auto-fit,minmax(268px,1fr));gap:18px;align-items:stretch}
.plans article{background:#fff;border:1px solid var(--line);border-radius:16px;padding:28px 24px;
  display:flex;flex-direction:column;position:relative}
.plans article.best{border-color:var(--blue);box-shadow:0 18px 44px -26px rgba(31,140,255,.7)}
.rib{position:absolute;top:-11px;left:24px;background:var(--blue);color:#fff;font-size:11.5px;font-weight:800;
  border-radius:99px;padding:4px 12px}
.plans h3{font-size:16px;font-weight:800;color:var(--ink-2)}
.plans .p{font-size:32px;font-weight:800;letter-spacing:-.04em;margin:8px 0 2px;font-variant-numeric:tabular-nums}
.plans .p small{font-size:14px;font-weight:700;color:var(--ink-3);margin-left:3px;letter-spacing:0}
.plans .q{font-size:14px;color:var(--blue);font-weight:700;margin-bottom:14px}
.plans ul{margin:0 0 22px;padding:0;list-style:none;display:grid;gap:9px;font-size:14.5px;color:var(--ink-2)}
.plans li{padding-left:20px;position:relative}
.plans li::before{content:'';position:absolute;left:2px;top:7px;width:10px;height:6px;
  border-left:2.2px solid var(--blue);border-bottom:2.2px solid var(--blue);transform:rotate(-45deg)}
.plans .btn{margin-top:auto;display:block;text-align:center;background:var(--blue);color:#fff;
  border-radius:9px;padding:13px;font-weight:800;font-size:15px}
.plans .btn:hover{background:var(--blue-d)}
.plans .btn.ghost{background:#fff;color:var(--ink-2);border:1px solid #d8dce2}
.plans .btn.ghost:hover{border-color:var(--ink-3)}

/* ── 자주 묻는 것 ── */
.faq .in{max-width:820px}
details{border-bottom:1px solid var(--line);padding:18px 0}
summary{font-size:16.5px;font-weight:700;cursor:pointer;list-style:none;display:flex;align-items:center;gap:10px}
summary::-webkit-details-marker{display:none}
summary::after{content:'+';margin-left:auto;color:var(--ink-3);font-size:20px;font-weight:400}
details[open] summary::after{content:'−'}
details p{margin-top:11px;font-size:15px;color:var(--ink-2);line-height:1.78}
details p b{color:var(--ink)}

footer{background:#0e1620;color:#8fa0b2;padding:46px 0}
.fb{display:flex;align-items:center;gap:9px;font-size:17px;font-weight:800;color:#fff;letter-spacing:-.03em}
.fb .mk{width:24px;height:24px;border-radius:7px;background:linear-gradient(140deg,#3f9bff,#0f5fc4);
  display:grid;place-items:center;color:#fff;font-size:12px}
footer p{margin-top:10px;font-size:13.5px}
footer .links{margin-top:18px;display:flex;gap:20px;font-size:14px}
footer .links a:hover{color:#fff}

@media (max-width:900px){
  .menu{display:none}
  .demo-body{grid-template-columns:1fr}
  .demo-fig{border-right:0;border-bottom:1px solid var(--line)}
  section.split .in{grid-template-columns:1fr;gap:34px}
  .mock{grid-template-columns:1fr}
  .two{grid-template-columns:1fr}
  .mo{display:inline}
  section.band,section.split,section.price,section.faq,section.dark{padding:60px 0}
  .hero{padding:52px 0 66px}
}
@media (prefers-reduced-motion:reduce){*{animation:none !important;transition:none !important}}